The present invention relates generally to scroll type machines, and more particularly to an improved muffler plate for scroll machines.
Scroll machines are generally provided with a hermetic outer shell. A muffler plate is often used to define a muffler chamber and a main chamber within the shell, each being at a different pressure during normal operation. A scroll assembly is disposed within the main chamber of the shell and includes an orbiting and a non-orbiting scroll member, each having spiral wraps which are mutually intermeshed and define at least one enclosed space of progressively changing volume between a suction pressure region and a discharge pressure region. A flow passage is formed through an end plate of one of the scroll members which allows fluid communication along a flow path between the enclosed space and the muffler chamber, and eventually through a port formed in the hermetic shell. As a result, the muffler plate must allow fluid communication between the enclosed space and the muffler chamber, while effectively sealing the muffler chamber from the main chamber to reduce leakage and enhance the efficiency of the scroll machine.
The muffler plate defines a face for engaging a seal disposed at an interface between the muffler chamber and the main chamber. To maintain effective isolation between the muffler chamber and the main chamber, the muffler plate face should remain in a flat and undistorted condition. Distortion of the face of the muffler plate may be caused for any of several reasons. First, inaccurate alignment or stress where the muffler plate is affixed to the scroll machine may distort the face defined by the muffler plate. Second, the difference in pressure between the muffler chamber and main chamber during normal operation causes a pressure gradient acting across the muffler plate, which may also distort the face. Third, operation of the scroll machine generally creates heat in various locations in the shell, and the resulting heat transfer may cause thermal distortion of the face of the muffler plate.
Accordingly, it is an object of the present invention to provide an improved muffler plate and seal configuration which reduces distortion of the muffler plate face and thereby reduces fluid leakage between the muffler chamber and the main chamber.
Additional advantages and features of the present invention will become apparent from the subsequent description and the appended claims, taken in conjunction with the accompanying drawings.